designPatternGuru/DesignPatternGuru/Observer/Observers/ISubject.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Observer.Observers
{
    internal interface ISubject
    {
        void Attach(IObserver observer);

        void Detach(IObserver observer);

        void Notify();
    }
}